28781684 has 12 divisors (see below), whose sum is σ = 50502144. Its totient is φ = 14352504.

The previous prime is 28781653. The next prime is 28781689. The reversal of 28781684 is 48618782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7862 + ... + 10925.

It is an arithmetic number, because the mean of its divisors is an integer number (4208512).

Almost surely, 2^28781684 is an apocalyptic number.

It is an amenable number.

28781684 is a deficient number, since it is larger than the sum of its proper divisors (21720460).

28781684 is a wasteful number, since it uses less digits than its factorization.

28781684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19174 (or 19172 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 28781684 is about 5364.8563820479. The cubic root of 28781684 is about 306.4587789757.

The spelling of 28781684 in words is "twenty-eight million, seven hundred eighty-one thousand, six hundred eighty-four".